/Engine/Source/Editor/UnrealEd/Classes/Animation/DebugSkelMeshComponent.h
Rebuilds the fixed parameter on the mesh to mesh data, to be used if the editor has changed a vert to be fixed or unfixed otherwise the simulation will not work bInvalidateDerivedDataCache can only be false during previewing as otherwise the changes won't be correctly saved
void RebuildClothingSectionsFixedVerts ( bool bInvalidateDerivedDataCache )